A reefer or refrigerated container includes a refrigerator or freezer for adjusting the internal temperature thereof to transport farm, livestock, and fishery products requiring the maintenance of freshness, or chemical products or pharmaceutical products requiring chemical stability.
In order to store the farm, livestock, and fishery products, the chemical products, the pharmaceutical products, or the like in safe custody while maintaining their qualities within the refrigerated container, the inside of the refrigerated container is required to be maintained continuously in a preset state. Thus, it is required that the internal state of the refrigerated container should be monitored and the refrigerated container should be controlled depending on information regarding the monitored internal state.
To this end, a refrigerated container monitoring system can be provided at a means of transport such as a trailer, a ship, or an aircraft which is moved with refrigerated containers loaded thereon, or a container yard where the refrigerated containers are piled up on top of one another in the movement process of the refrigerated container
As examples of a technology related to such a refrigerated container monitoring system, there are disclosed Korean Patent Registration No. 10-0972128 entitled “Refrigerated Container Communication Device and Refrigerated Container Monitoring System and Method Using The Same” and Korean Patent Laid-Open Publication No. 10-2006-0090884 entitled “Refrigerated Container Monitoring System Using Wireless Modem and Control method Thereof”.
The above patent document, the refrigerated container monitoring system disclosed in Korean Patent Registration No. 10-0972128 includes: an active tag installed at a refrigerated container, the active tag being configured to be initialized and having stored therein a unique number of the refrigerated container, which is transferred thereto, and configured to read and output information regarding the operating state of the refrigerated container monitoring system; a smart reader configured to receive the information regarding the operating state of the refrigerated container monitoring system from the active tag through wireless communication; and output the received the information regarding the operating state of the refrigerated container monitoring system; and a server configured to receive the information regarding the operating state of the refrigerated container monitoring system from the smart reader through wired communication and process the received information, the server being configured to assign the unique number. The refrigerated container monitoring system has an advantage in that it can manage a 4-pole type refrigerated container in an easy and efficient manner, and can acquire information regarding a corresponding position through the unique number assigned to the active tag, a unique ID of the smart reader and the like so that a corresponding refrigerated container can be found easily.
In the refrigerated container monitoring system disclosed in disclosed in Korean Patent Registration No. 10-0972128, a 4-pole socket that can be formed at a control panel for controlling a refrigerator of the refrigerated container is used as a communication port for monitoring the refrigerated container. A 4-pole socket cable is connected to the 4-pole socket of the refrigerated container, and the 4-pole socket cable connected to a plurality of refrigerated containers is connected to a reefer container socket (RCS) box having a built-in remote monitoring unit (RMU). The RCS box is configured to be connected to a master modem by means of power line communication so that information regarding the state of the plurality of refrigerated containers is transferred to a management server through the master modem.
However, the refrigerated container monitoring system based on the 4-pole socket entails a problem in that it is possible to monitor the refrigerated container but it is impossible to remotely control the operation of the refrigerated container according to a result of the monitoring, and in that since there frequently occurs the case where the 4-pole socket is not provided depending on the kind or the manufacture company of the refrigerated container, the refrigerated container monitoring system cannot be universally applied to the refrigerated container.
The refrigerated container monitoring system disclosed in Korean Patent Laid-Open Publication No. 10-2006-0090884 is a system that includes a plurality of refrigerated container each having a download port through which information can be transmitted to the outside. The refrigerated container monitoring system includes: one or more wireless slave terminals each connected to a download port of each refrigerated container and configured to convert the operation information of the refrigerated container into a wireless signal and transmit the converted operation information through the download port; and a central control server configure to receive the wireless signal from each wireless slave terminal to collect the operation information of the refrigerated container and monitor each refrigerated container, process the collected operation information of the refrigerated container and display the processed operation information to a manager, and give an alarm to the manager if abnormal information is detected from a specific refrigerated container.
However, the refrigerated container monitoring system disclosed in Korean Patent Laid-Open Publication No. 10-2006-0090884 encounters a problem in that the wireless communication is used and thus instability of the refrigerated container monitoring system is increased by signal interference or noise.
Meanwhile, a system has been developed and used which monitors a refrigerated container based on the power line communication through a slave modem that can be formed at the control panel of the refrigerated container. Such a power line communication type refrigerated container monitoring system is configured such that a power line is connected to the slave modem of the refrigerated container, the power line connected to a plurality of refrigerated containers is connected to a reefer container socket (RCS) box having a built-in a remote monitoring unit (RMU), and the RCS box is connected to a master modem by means of power line communication so that information regarding the state of the plurality of refrigerated containers is transferred to a management server through the master modem.
Such a power line communication type refrigerated container monitoring system still has a problem in that it is possible to monitor the refrigerated container and remotely control the operation of the refrigerated container according to a result of the monitoring, but there frequently occurs the case where the slave modem is not provided depending on the kind or the manufacture company of the refrigerated container, thus the refrigerated container monitoring system cannot be universally applied to the refrigerated container. Accordingly, a refrigerated container which is not monitored by the power line communication type refrigerated container monitoring system causes a worker to suffer from an inconvenience of having to monitor personally in a field, and the installation of the slave modem and the master modem leads to an increase in the installation cost.
In the meantime, the conventional refrigerated container monitoring system has a disadvantage in that since the amount of power consumed is not measured, power consumption cost can be arbitrarily assigned by an owner or a manager of a space where the refrigerated container monitoring system is constructed, which may cause an unreasonable situation.